• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2002.05a
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• pp.399-404
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• 2002

Analyzing acoustic-structural systems such as automobiles and aircraft the FRF-based substructuring method is one of the most powerful tools. In this paper, an optimization procedure far the engine mount system of passenger car has been presented using the design sensitivity analysis based on the multi-domain FRF-based substructuring formulation. The proposed method is applied to an optimization problem of the engine mount system, of which objective is to minimize the interior sound over the concerned rpm range. The design variables selected are the stiffnesses of the engine mounts and bushes. Plugging the gradient information calculated by the proposed method into nonlinear optimization software, we can obtain the optimal stiffnesses of the engine mounts and bushings through design iterations. The optimized interior noise in the passenger car shows that the proposed method is very useful in the realistic situation.

• Proceedings of the Computational Structural Engineering Institute Conference
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• 2001.10a
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• pp.485-492
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• 2001

The dynamic analysis model is developed with the high-speed train (KTX) and a 2-span continuous prestressed concrete box girder bridge with a double track. The analytical results are compared with the dynamic field test results and found to be valid to yield quite accurate dynamic responses. The various trainset models with different number of cars are developed and compared with the results of the regular 20-car trainset model. It is concluded that the reduced trainset models, such as 7-car and 10-car models, cannot exactly produce the dynamic responses of bridges, especially when the train speed is high. Under the coincidence condition of two trains traveling with resonance velocity in the opposite directions, it is found that the impact factor under two-way coincidence is three times larger than that under one-way traffic. Consequently, for the bridge with a double-track it is necessary to check not only the dynamic responses of the bridge with one-way traffic but those with two-way coincidence.

• Proceedings of the KSR Conference
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• 2008.11b
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• pp.1697-1702
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• 2008

The objective of the review is to introduce the evaluation method of welding joint designs by using forces extracted from FE models. This evaluation method is currently being used for the Southeastern Pennsylvania Transportation Authority (SEPTA) project in the United States by request of the customer Engineer. The evaluation method was applied to critical joints connected by Fillet or Partial Joint Penetration (PJP) welds in car body structure for SEPTA project. The additional manual analysis is required based on the fact that Technical Specification in the United States requires the Contractor to apply Complete Joint Penetration (CJP) welds to all structural connections in Car body. However, in the car body design for Septa project there are some areas where CJP welds are not applied due to structural and manufacturing problems.

• Archives of design research
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• v.16 no.3
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• pp.371-380
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• 2003

Modern consumers expect the goods which is sewed more sensitive and emotional satisfaction. It is necessary to apply the knowledge of sensibility analysis to the design of car. The design of wheel for car is regarded as important because consumers want to have unique cars and spend on decorating their cars. This study is to understand the image of consumer's idea about the design of wheel for far through the sensibility analysis that is understood from a part of new design way. According to consumers'needs and emotion, the images of 'harmonious', 'fresh' and 'strong' are representative for the design of wheel for car. The wheel of spoke type stands for the image of 'harmonious', the wheel of mesh type for the image of 'fresh' and the wheel of dish type for the image of 'strong'. Therefore, the emotional image that consumers have of the product is extracted by the sensibility Analysis. In turn, the suggestion of a design direction that satisfies the consumers is possible.

• Journal of Korean Society of Transportation
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• v.30 no.2
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• pp.127-136
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• 2012

Multi-car rear-end collision accidents have three categories: sequential collision from the rear which is commonly referred to as chain reaction collision, sequential collision from the front, and mixed-order collision. This paper suggests several effective methods of reconstruction analysis for multi-car rear-end collision accidents. First, by incorporating the traditional empirical method which uses vehicle damage caused by brake dive and passenger injuries, with results of theoretical analysis made within mechanics of rigid body, it is made possible for the method to be put to immediate practical use. A methodology to precisely analyze multi-car rear-end collision accidents was suggested using a simulation program simultaneously with a video event data recorder which is starting to be widely used in domestic vehicles. To go beyond the simple intuitive analysis of the video event data recorder, the simulation analysis based on the results of video analysis was executed to acquire various information, so that the causes and responsibility could be clearly stated.

• Journal of Energy Engineering
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• v.20 no.1
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• pp.54-62
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• 2011

Since the release of mid-term domestic GHG goals until 2020, in 2009, some various GHG reduction policies have been proposed. In case of the transportation sector for the mid-term domestic GHG goals, it targets to reduce about 30% regarding the doemstic economic growth until 2020. A major reduction method in passenger cars considers an electric car. In this study we analyze some various scenarios to compare between internal combustion engine car and electric car using break-even analysis. Through the analysis we suggest a subsidy policy for electric car.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 1993.04a
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• pp.93-100
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• 1993

With increasing technology, requirement to car noise and related dynamics are getting competitive keypoint. Unfortunately, vibro - acoustic behavior of a car is nowadays only possible after development of prototypes. But, obviously, in the Area of Research, many of Industrials, Universities and research centers try to codevelop the design tools to predict the vibro-acoustic behaviors. At this stage, it is more realistic to represent the existing technologies in order for the engineer to get their own know-how to design and to Integrate existing techniques, to setup their test facility, and to develope some tools with which they can successfully predict noise levels of car in the design phase. Moreover, most of the theories which will be represented in this paper can be used in the design phase. At any way, finding the cause of trouble shooting is more urgent than the design of a car to the test engineer. In this paper, transfer path analysis, noise source identification, and the key test method of modal analysis is introduced. Later, if I get the opportunity to present in KSNVE, the approach method of modal analysis is introduced. Later, if I get the opportunity to present in KSNVE, the approach method of finding characteristics of joint and welding part will be introduced. Most parts of this paper was quoted from the papers of LMS.

• The Journal of the Institute of Internet, Broadcasting and Communication
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• v.17 no.5
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• pp.17-23
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• 2017

A connected car's major factor is connectivity and it can be applied for new concept smart PC hardware and software design method of digital virtual assistance using voice recognition engine at server when infotainment functions are implemented because internet connecting LTE or 5G wireless mobile communication is always is possible. In this paper, a hardware architecture of smart auto-PC and software architecture based on GENIVI platform, and necessary functions are proposed. Also an effective analysis and design method of connected car infotainment system will be presented by showing user requirement analysis using object-oriented method, flowchart and screen design.

• Transactions of the Korean Society of Automotive Engineers
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• v.15 no.4
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• pp.33-40
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• 2007

Crashworthiness design is of special interest in automotive industry and in the transportation safety field to ensure the vehicle structural integrity and more importantly the occupant safety in the event of the crash. Front side assembly is one of the most important energy absorbing components in relating to the crashworthiness design of vehicle. The structure and shape of the front side assemblies are different depending on auto-makers and size of vehicles. Thus, it is not easy to grab an insight on designer's intention when you glance at a new front side member without experiences. In this paper, we have performed the explicit nonlinear dynamic finite element analysis on the front side assembly of passenger cars to identify the mechanical roles of major parts in relation to collapse modes from the viewpoint of reverse engineering. To do this, we have performed crash FE analysis for the two different assemblies of small car and heavy passenger car and have compared dynamic behaviors of the two.

• 한국전산유체공학회:학술대회논문집
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• 1998.05a
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• pp.99-109
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• 1998

This paper describes the analysis of flow and aeroacoustic field around a car-like body. The governing equations, 3-D unsteady incompressible Navier-Stokes equations, are solved with the iterative time marching scheme. The Chimera grid technique has been applied to efficiently simulate the flow around the side-view mirror, After the flow field analysis has been converged, the aerodynamic noise analysis of the side-view mirror has been performed by solving Ffowcs Williams and Hawkings equation. From the present numerical simulation, the A- and C-pillar vortex are evidently shown and the aerodynamic noise level induced by the side-view mirror is predicted to about 100dB.